title: Relationship between single nucleotide polymorphism of interleukin-18 and susceptibility to pulmonary tuberculosis in the Chinese Han population.
abstract: Interleukin-18 (IL-18) is a multi-functional cytokine capable of inducing either Th1 or Th2 polarization depending on the immunologic milieu. IL-18 may influence the host response to Mycobacterium tuberculosis (M.tb) infection. To investigate the relationship between single nucleotide polymorphisms of the IL-18 and susceptibility to pulmonary tuberculosis in the Chinese Han population, the IL-18 gene was sequenced to detect polymorphisms and to examine the genotype frequencies in 300 patients and 702 healthy controls. DNA sequencing revealed three IL-18 variants: rs1946518, rs5744247, and rs549908. It also revealed that allele A of rs1946518 confers a 1.47-fold increased risk of developing tuberculosis (TB) (P = 0.0001, OR [95%CI] = 1.47 [1.21-1.78]), and that the C allele of rs5744247 confers a 0.77-fold decreased risk of disease (P = 0.01, R [95%CI] = 0.77 [0.632-0.937]). The genotypes rs1946518, rs5744247 and rs549908 were found to be significantly associated with TB. Estimation of the frequencies of haplotypes revealed a potential risk haplotype AGA (P = 0.01, OR [95%CI] = 1.41 [1.15-1.72]) and a protective haplotype CCA (P = 0.01, OR [95%CI] = 0.70 [0.57-0.85]) for TB. The present findings suggest that polymorphisms in the IL-18 gene may affect susceptibility to TB and increase the risk of developing the disease in the Chinese Han population.
authors.affiliation: Shanghai Key Laboratory of Mycobacterium Tuberculosis, Shanghai Pulmonary Hospital Affiliated to Tongji University School of Medicine, 507 Zhengmin Rd, Shanghai, China.
authors.forename: Min
authors.initials: M
authors.lastname: Han
authors.forename: Jun
authors.initials: J
authors.lastname: Yue
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Lian
authors.forename: Yan-Lin
authors.initials: YL
authors.lastname: Zhao
authors.forename: Hong-Xiu
authors.initials: HX
authors.lastname: Wang
authors.forename: Li-Rong
authors.initials: LR
authors.lastname: Liu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D044466:Asian People; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D020382:Interleukin-18 / Q000235:genetics* / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000276:immunology / Q000472:pathogenicity; D020641:Polymorphism, Single Nucleotide; D014397:Tuberculosis, Pulmonary / Q000235:genetics* / Q000276:immunology*; D055815:Young Adult
chemical_list: D020382:Interleukin-18